blois 2008 suzy collin-zahn luth, observatoire de paris meudon agn, massive black holes, accretion...
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Blois 2008
Suzy Collin-ZahnSuzy Collin-Zahn
LUTH, Observatoire de Paris MeudonLUTH, Observatoire de Paris Meudon
AGN, MASSIVE BLACK HOLES, ACCRETIONAGN, MASSIVE BLACK HOLES, ACCRETION
ARE AGN FACTORIES OF HIGH ENERGY ARE AGN FACTORIES OF HIGH ENERGY PARTICLES AND PHOTONS?PARTICLES AND PHOTONS?
OROR
Blois 2008
THE CONTEXTTHE CONTEXT
DICHOTOMY RADIO LOUD / RADIO QUIET OBJECTS DICHOTOMY RADIO LOUD / RADIO QUIET OBJECTS AND JETS / WINDSAND JETS / WINDS
STRONG AND WEAK ACCRETORSSTRONG AND WEAK ACCRETORS
CONCLUSIONCONCLUSION
Blois 2008
THE CONTEXTTHE CONTEXT
DICHOTOMY RADIO LOUD / RADIO QUIET OBJECTS DICHOTOMY RADIO LOUD / RADIO QUIET OBJECTS AND JETS / WINDSAND JETS / WINDS
STRONG AND WEAK ACCRETORSSTRONG AND WEAK ACCRETORS
CONCLUSIONCONCLUSION
Blois 2008
1.1. Active Galactic Nuclei: from quasars (L=10Active Galactic Nuclei: from quasars (L=1046-4846-48 erg/s) to erg/s) to Seyfert galaxies (L=10Seyfert galaxies (L=1043-4643-46 erg/s), and Low Luminosity erg/s), and Low Luminosity AGN (L=10AGN (L=1040-4340-43 erg/s) erg/s)
RECALL OF SOME WELL-KNOWN FACTSRECALL OF SOME WELL-KNOWN FACTS
2. Power derived from accretion onto a supermassive black 2. Power derived from accretion onto a supermassive black holehole
3. BH present in ALL NUCLEI of galaxy, M(BH) from L=103. BH present in ALL NUCLEI of galaxy, M(BH) from L=1010 10 to 10to 1055 M M , M(BH) ~ M(Bulge)/1000, M(BH) ~ M(Bulge)/1000
4. « Unified Scheme »4. « Unified Scheme »
Blois 2008
Black hole
Absorbing torus
Narrow line region
Broad line region
Accretion disk
(RL or RQ)
(FRI) (FRII)
Wind
radio galaxies
LINERs
Blois 2008
SOME FIDUCIAL VALUESSOME FIDUCIAL VALUES
Eddington luminosityEddington luminosity
gravitational radius:gravitational radius: =1.5 10=1.5 101313 MM88 cm ~10cm ~10-5 -5 pcpc
bolometric luminositybolometric luminosity
where is the accretion ratewhere is the accretion rate
rmaximum radiation efficiency of mass-energy conversionrmaximum radiation efficiency of mass-energy conversion0.057 for a Schwarzschild BH, R(ISCO)=6Rg0.057 for a Schwarzschild BH, R(ISCO)=6Rg
0.3 for a maximally rotating Kerr BH, R(ISCO)~1Rg0.3 for a maximally rotating Kerr BH, R(ISCO)~1Rg
M•
€
Lbol = ε M•
c 2
€
Lbol = ε M•
c 2
QuickTime™ et un décompresseurGIF sont requis pour visualiser
cette image.
QuickTime™ et un décompresseurGIF sont requis pour visualiser
cette image.
= 1.3 10= 1.3 104646 MM88 erg/serg/s
€
M•
= ε
0.1 L46 0.6 Mo/yr
€
M•
= ε
0.1 L46 0.6 Mo/yr
Blois 2008
HOW TO FUEL BLACK HOLES?HOW TO FUEL BLACK HOLES?
The angular momentum (The angular momentum (GMR)GMR)1/21/2 must be transported outward! must be transported outward!
Major and minor mergers (quasars)Major and minor mergers (quasars)Tidal interactions between galaxies (luminous Seyfert)Tidal interactions between galaxies (luminous Seyfert)
Bars, bars within bars, nonaxisymmetric potentials (weak Seyfert)Bars, bars within bars, nonaxisymmetric potentials (weak Seyfert)Dynamical friction of molecular clouds (LLAGN)…Dynamical friction of molecular clouds (LLAGN)…
1. At large distances (≥ 100pc)1. At large distances (≥ 100pc)
2. At small distances (<1pc)2. At small distances (<1pc)
« ACCRETION DISKS »« ACCRETION DISKS » local turbulent viscosity (MRI, possibly)local turbulent viscosity (MRI, possibly)
3. At intermediate distances3. At intermediate distances
Still unknown! Gravitational instability?Still unknown! Gravitational instability?
or global transport of AM via an organized magnetic field?or global transport of AM via an organized magnetic field?
Blois 2008
THE CONTEXTTHE CONTEXT
DICHOTOMY RADIO LOUD / RADIO QUIET OBJECTS DICHOTOMY RADIO LOUD / RADIO QUIET OBJECTS AND JETS / WINDSAND JETS / WINDS
STRONG AND WEAK ACCRETORSSTRONG AND WEAK ACCRETORS
CONSLUSIONCONSLUSION
Blois 2008
In local UniverseIn local Universe
Luminous AGN : ~ 1% of all galaxiesLuminous AGN : ~ 1% of all galaxies
Low Luminosity AGN : ~ 40% of all galaxiesLow Luminosity AGN : ~ 40% of all galaxies
The remainder 60%: dormant BHThe remainder 60%: dormant BH
Blois 2008
€
m •
= M•
/ Mcrit
•
, with M•
crit = LEdd /c 2
m •
< .001: weak accretors
m •
> .01: strong accretors
€
m •
= M•
/ Mcrit
•
, with M•
crit = LEdd /c 2
m •
< .001: weak accretors
m •
> .01: strong accretors
ACCRETION DISKS:ACCRETION DISKS:
INFLUENCE OF THE ACCRETION RATEINFLUENCE OF THE ACCRETION RATE
Blois 2008
Spectral distribution of Seyfert and RQQ,Spectral distribution of Seyfert and RQQ,no radio or gamma radiation, everything is thermal!no radio or gamma radiation, everything is thermal!
synchrotronsynchrotron
dustdust
cold accretion diskthermal Compton
cold accretion diskthermal Compton
hot corona
thermal Compton
hot corona
thermal Comptoninverse
Compton
inverse
Compton
thermal emission
accretion
thermal emission
accretion
A. STRONG ACCRETORSA. STRONG ACCRETORS
Observations by Sanders et al. 1989
Blois 2008
Thin disks, H/R <<0.1, optically thick, emit the « Big Blue Bump »Thin disks, H/R <<0.1, optically thick, emit the « Big Blue Bump »SeyfertSeyfert
Quasars, Narrow Line Seyfert 1 (NLS1s)Quasars, Narrow Line Seyfert 1 (NLS1s)
« slim » disks, H/R ~0.1, optically thick, radiation pressure, « slim » disks, H/R ~0.1, optically thick, radiation pressure, emit the « Big Blue Bump »emit the « Big Blue Bump »
€
0.1< m •
< 3
€
0.1< m •
< 3
€
3 < m •
<10
€
3 < m •
<10
I.I.
II.II.
« Thick » disks, H/R~1, optically thick, radiation pressure,« Thick » disks, H/R~1, optically thick, radiation pressure,
emit soft X-rays, emit soft X-rays, photons cannot escape, thusphotons cannot escape, thus
Some low mass NLS1s (10Some low mass NLS1s (106-76-7Mo), in growing processMo), in growing process
€
10 < m •
€
10 < m •
III.III.
€
L /LEdd ~ 1 << m.
€
L /LEdd ~ 1 << m.
Blois 2008
CONTROVERSY ABOUT THICK DISKSCONTROVERSY ABOUT THICK DISKS
Do these boulimic accretors exist? Do these boulimic accretors exist?
MHD simulations seems to show that if m >> 10 at large distance, MHD simulations seems to show that if m >> 10 at large distance,
strong outflows are expelled at smaller distance, strong outflows are expelled at smaller distance,
and theand the accretion rate on the BHaccretion rate on the BH remains limited remains limited
at the Eddington value.at the Eddington value.
.
Blois 2008
NO HARD X-RAYS ARE EXPECTED FROM THESE DISKS
proof of the presence of a hot medium emitting the hard X-rays proof of the presence of a hot medium emitting the hard X-rays whose emission is « reflected » by the diskwhose emission is « reflected » by the disk
Inte
nsity
Energy in keV
MCG _6_30_15
Iron K line
Relativistic profile of FeK Relativistic profile of FeK the disk extends down to ~10Rg, and the disk extends down to ~10Rg, and sometimes to ~1Rg sometimes to ~1Rg ISCO of a rapidly spinning BH ISCO of a rapidly spinning BH
BUT
Fabian et al. 2006
Blois 2008
The reflection model: radiatively coupled disk + coronaThe reflection model: radiatively coupled disk + corona
Done, Gierlinski , 2004Done, Gierlinski , 2004
Same radiation coupling, but more realistic model : Same radiation coupling, but more realistic model : disk + « magnetic flares »disk + « magnetic flares »
Corona Corona Compton-Compton-
cooled cooled by UVby UV
photonsphotons
Disk heated byDisk heated by gravitationalgravitational
release release AND X-raysAND X-rays
Blois 2008
Optically thin, geometrically thick, hot (relativistic) disks, Optically thin, geometrically thick, hot (relativistic) disks, emitting mainly radio and X-rays,emitting mainly radio and X-rays,
Gas falls into the BH before radiating, thus Gas falls into the BH before radiating, thus
€
L /LEdd << m •
€
L /LEdd << m •
LLAGN, radio galaxies FRI (M87..), Galactic CenterLLAGN, radio galaxies FRI (M87..), Galactic Center
B. WEAK ACCRETORS
€
m •
≤ 0.001
€
m •
≤ 0.001
Blois 2008
Inflated codona, or…Inflated codona, or………suppression of the inner suppression of the inner regions of accretion diskregions of accretion disk
The « Big Blue Bump » does not existThe « Big Blue Bump » does not exist
Blois 2008
CONTROVERSY ABOUT THESE DISKSCONTROVERSY ABOUT THESE DISKS
Which model for these anorexic accretors? Which model for these anorexic accretors?
ADAF, ADIOS, CDAF… RIAFADAF, ADIOS, CDAF… RIAF
Is there also a jet?Is there also a jet?
Blois 2008
Yuan, Quataert, Narayan, 2003
Synchrotron and Inverse Compton by thermal electrons
Synchrotron and Inverse Compton by non-thermal electrons
(jet or ADAF?) bremsstrahlung
ADAF+JET FOR A « QUIESCENT » BH: ADAF+JET FOR A « QUIESCENT » BH: THE GALACTIC CENTERTHE GALACTIC CENTER
measured M~3 10measured M~3 10-6-6 M Mo o /yr/yr L (for L (for ~0.1) should be ~ 10 ~0.1) should be ~ 1041 41 erg/serg/s
quiescent
flaring
.BUT measured L~ 10BUT measured L~ 1036 36 erg/serg/s L/LL/LEdd Edd ~ 3 10~ 3 10-9-9,, ~ 10~ 10-6-6
Blois 2008
ADAF+JET MODEL FOR A FRI GALAXYADAF+JET MODEL FOR A FRI GALAXY
L/LL/LEdd Edd ~ 3 10~ 3 10-4-4
ADAFJet
Wu, Yuan, Cao, 2008
Blois 2008
CONCLUSION:CONCLUSION:
BOTH STRONG AND WEAK ACCRETORS ARE BOTH STRONG AND WEAK ACCRETORS ARE RADIATIVELY INEFFICIENTRADIATIVELY INEFFICIENT
DISKS MUST PRODUCE OUTFLOWS TO DISKS MUST PRODUCE OUTFLOWS TO EVACUATE THEIR ENERGYEVACUATE THEIR ENERGY
Blois 2008
THE CONTEXTTHE CONTEXT
DICHOTOMY RADIO LOUD / RADIO QUIET OBJECTS DICHOTOMY RADIO LOUD / RADIO QUIET OBJECTS AND JETS / WINDSAND JETS / WINDS
STRONG AND WEAK ACCRETORSSTRONG AND WEAK ACCRETORS
CONCLUSIONCONCLUSION
Blois 2008
AGN are divided in « Radio Loud » (RL) and « Radio Quiet » (RQ)AGN are divided in « Radio Loud » (RL) and « Radio Quiet » (RQ)
Sikora, Stawarz, Lasota, 2007
BLRG
LINERS
RQQ
RLQ
SEYFERTS
FRI
Blois 2008
Mc Lure, Dunlop 2004
With a complete sample of quasars (SDSS)With a complete sample of quasars (SDSS)
Number of RLQ are less than 10% of RQQNumber of RLQ are less than 10% of RQQ
R = Lradio(5GHz) / Lopt
Blois 2008
Log(L/Ledd)
LINERS
RQQSEYFERTS
RADIO LOUDNESS DEPENDS ON THE EDDINGTON FACTORRADIO LOUDNESS DEPENDS ON THE EDDINGTON FACTOR
BLRG
RLQ
FRI
Blois 2008
LINERS, SEYFERTS
RQQ
RADIO LOUDNESS DEPENDS ON M(BH)RADIO LOUDNESS DEPENDS ON M(BH)
BLRG
RLQ
FRI
Blois 2008
1. 1. LocallyLocally RL are exclusively in elliptical galaxies, RL are exclusively in elliptical galaxies,
RQ in spiral galaxies RQ in spiral galaxies
DIFFERENCES BETWEEN RL AND RQDIFFERENCES BETWEEN RL AND RQ objectsobjects
2. RLs are associated with non-thermal relativistic collimated 2. RLs are associated with non-thermal relativistic collimated jetsjets,,
RQs seem associated with thermal non-collimated RQs seem associated with thermal non-collimated windswinds
(detected by Broad Absorption Lines and X-ray absorbers)(detected by Broad Absorption Lines and X-ray absorbers)
3. Several more subtile properties, not understood 3. Several more subtile properties, not understood
(i.e. intense FeII lines only in RQs)(i.e. intense FeII lines only in RQs)
I. HIGH LUMINOSITY AGN
WHY?WHY?
Blois 2008
JETS VERSUS WINDSJETS VERSUS WINDS
Jets are launched at R ≤ 1000 Rg (VLBI)Jets are launched at R ≤ 1000 Rg (VLBI)
Winds are launched at R ≥ 10000RgWinds are launched at R ≥ 10000Rg
OBSERVATIONSOBSERVATIONS
Jets have relativistic bulk velocities and are made of relativistic Jets have relativistic bulk velocities and are made of relativistic particlesparticles
Winds have velocities from few hundreds km/s to c/10 and Winds have velocities from few hundreds km/s to c/10 and consist of warm (10consist of warm (105-6 5-6 K) thermal gasK) thermal gas
Blois 2008
Magnetic field is indispensable to explain extended jet acceleration:Magnetic field is indispensable to explain extended jet acceleration:
1. Centrifugally driven flow1. Centrifugally driven flow
2. Extraction of the 2. Extraction of the rotational energyrotational energy of the BHof the BH: : field connects the BH to the diskfield connects the BH to the disk
(Blandford-Znajek, 1977) (Blandford-Znajek, 1977)
JET DRIVING MECHANISMJET DRIVING MECHANISM
Jets might be linked with the spin of the BHJets might be linked with the spin of the BH
Blois 2008
BLACK HOLE SPINBLACK HOLE SPIN
1. Even RQ AGN have spinning BH (FeK line)1. Even RQ AGN have spinning BH (FeK line)
2. Cosmological evolution of AGN requires large fraction of 2. Cosmological evolution of AGN requires large fraction of spinning BHs (mass-conversion efficiency must be > 0.06)spinning BHs (mass-conversion efficiency must be > 0.06)
Measured by dimensionless angular momentum Measured by dimensionless angular momentum a = J/Jmax = cJ/GMa = J/Jmax = cJ/GM22
4. It is expected that 4. It is expected that aa increases with accretion AND with merger increases with accretion AND with merger of two BHsof two BHs
3. Power of the jet must increase with 3. Power of the jet must increase with aa
5. BHs increase with galaxy bulges, and a fraction of elliptical 5. BHs increase with galaxy bulges, and a fraction of elliptical galaxies (large bulges) are due to the merger of spirals galaxies (large bulges) are due to the merger of spirals
Elliptical galaxies favor high spin, therefore jetsElliptical galaxies favor high spin, therefore jets
Blois 2008
But it does not explain all:But it does not explain all:Other mechanisms must be at workOther mechanisms must be at work
1.1. Environnement can play a role:Environnement can play a role:spiral galaxies contain cold gas, ellipticals contain and are surrounded by hot gas
2. Geometry of the inner disk can play a role: 2. Geometry of the inner disk can play a role: thick or thinthick or thin
3. Density profile of the circumnuclear regions can play a role: 3. Density profile of the circumnuclear regions can play a role: cusp or corecusp or core
etc… etc…etc… etc…
Blois 2008
DO THEY HAVE JETS? YES! DO THEY HAVE JETS? YES!
Falcke et al; 2000
A sample of Low Luminosity AGNA sample of Low Luminosity AGN
Compact jet structure with flat spectra observed in 40% of LLAGNCompact jet structure with flat spectra observed in 40% of LLAGN
(bulge)
large M(BH) small M(BH)
II. LOW LUMINOSITY AGN II. LOW LUMINOSITY AGN
but no detailed mechanism proposed so farbut no detailed mechanism proposed so far
Blois 2008
FINALLY IS THE SOLUTION THIS ONE?FINALLY IS THE SOLUTION THIS ONE?
Radio Loud AGNRadio Loud AGN
Radio Quiet AGNRadio Quiet AGN
Blois 2008
Hawley, Balbus, 2002
OR ARE THE WIND AND THE JET COEXISTING?OR ARE THE WIND AND THE JET COEXISTING?
inner jets can be undetected in luminous AGNinner jets can be undetected in luminous AGN
WINDJET
Blois 2008
CONCLUSIONCONCLUSION
3. BAD NEWS:3. BAD NEWS: Only a small proportion of luminous AGN have Only a small proportion of luminous AGN have relativistic jets and non-thermal radiationrelativistic jets and non-thermal radiation
1. jets or high energy mechanisms can escape detection, if they 1. jets or high energy mechanisms can escape detection, if they are quenched close to the BHare quenched close to the BH
4. GOOD NEWS:4. GOOD NEWS: In low luminosity AGN (and basically all In low luminosity AGN (and basically all galaxies), jets and high energy processes take place close to galaxies), jets and high energy processes take place close to the central BHthe central BH
2. Jets in radio loud high luminosity AGN are likely driven by 2. Jets in radio loud high luminosity AGN are likely driven by spinning black holes, but other mechanisms must play a role spinning black holes, but other mechanisms must play a role
AND FINALLY, VERY LITTLE IS YET UNDERSTOOD!AND FINALLY, VERY LITTLE IS YET UNDERSTOOD!
Blois 2008
An exemple of a strong accretor (Ton S 180) modeled by a thick disk, An exemple of a strong accretor (Ton S 180) modeled by a thick disk, M(BH)=6 10M(BH)=6 1066 M Moo, m=60 , m=60
Kawaguchi, Piérens, Huré, 2003Kawaguchi, Piérens, Huré, 2003
Blois 2008
Caution: one defines sometimesCaution: one defines sometimes
€
M•
Edd = LEdd /εc 2, which gives M•
Edd = M•
crit /10 for ε = 0.1
€
M•
Edd = LEdd /εc 2, which gives M•
Edd = M•
crit /10 for ε = 0.1
Blois 2008
Wind driving mechanismWind driving mechanism
-radiation pressure driven from the diskradiation pressure driven from the disk
but « shielding » of the central source necessarybut « shielding » of the central source necessary
-centrifugally driven from disks threated by an open magnetic fieldcentrifugally driven from disks threated by an open magnetic field
- thermally or hydrodynamically driven from the hot corona- thermally or hydrodynamically driven from the hot corona
sketch of a sketch of a disk wind, disk wind,
centrifugally centrifugally and/or and/or
radiatively radiatively acceleratedaccelerated
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